A longitudinal study on a group of children who were originally examined in a special camp for juvenile-onset diabetic patients has been instituted. The primary documentation of microangiopathy changes involves the examination and recording of retinal vascular changes and assessing renal function. Changes involving larger vessels will be monitored by assessment of the cardiovascular status and arteries in the extremities. Paralleling these clinical examination observations, blood studies including rheology and selected blood chemistry determinations are performed.